Slide fastener stringer

ABSTRACT

The interlocking elements of a slide fastener stringer consisting of consecutive sections of a plastic wire have elongated leg portions parallel to each other, transverse to the sequence of elements, and linked by connecting portions common to two adjacent elements. The fastener elements are secured to a carrier tape by two rows of thread loops offset from the connecting portions in opposite directions longitudinally of the leg portions.

L United States Patent H 1 3,694,868 Spindler 1 1 Oct. 3, 1972 [54]SLIDE FASTENER STRINGER 3,249,976 5/1966 Burbank ..24/205. 16 CInventor: w Spindler, Munich 3,290,747 12/1966 Blll'bdl'lk l6 C many3,412,438 11/1968 Sim ..24/205.16 C 3,484,906 12/1969 Yoshida..;..24/205.13 C [73] Assigneez Karl F. Nagele Feinmaschinenbau,

Stuttgart-Hohenheim, Germany FOREIGN PATENTS OR APPLICATIONS [22] Filed:Jan. 21, 1970 680,296 2/1964 Canada ..24/205.13 C

[21] Appl' 4708 Primary Examiner-*Bernard A. Gclak Attorney-Kelman andHerman [30] Foreign Application Priority Data .Ian. 23, 1969 Germany P19 03 339.7 1571 ABSTRACT The interlocking elements of a slide fastenerstringer CL-24/205-1 24/205153 C, 24/205-16 C consisting of consecutivesections of a plastic wire [51] ll!!- CLW; ..A44b 19/10,A44b 19/34 haveelongated leg portions parallel to each other, [58] held ofSearch'24/205'16 20513 205 C transverse to the sequence of elements, andlinked by connecting portions common to two adjacent ele- [56]References cued ments. The fastener elements are secured to a carrierUNTTED STATES PATENTS tape by two rows of thread loops offset from theconnecting portions in opposite directions longitudihally 3,015,8681/1962 Ruhrmann ..24/205.13 C v of the leg ponions 3,189,964 6/1965Galonska ..-...24/205.16 C 3,199,162 8/ 1965 Sohr ..24/205.16 C 7Claims, 6 Drawing Figures PATENTEDHBIB I912 SHEET 2 0F 3 Fig.4

INVENTORI WW u d M J PATENTEI] N 3 I97? SHEET 3 BF 3 AGE/V75 SLIDEFASTENER STRINGER This invention relates to slide fasteners, andparticularly to a slide fastener stringer essentially consisting of acarrier member such as a tape, a sequence of interlocking fastenerelements constituted by respective sections of a suitably shaped plasticwire, and fastening means securing the elements to the carrier member.In its more specific aspects, the invention is concerned with thefastening means and with the configuration of the elements which makesthe fastening means effective.

All continuous plastic slide fastener elements in present commercial useare derived from two basic shapes, a helix and a folded meander. Thebasic shapes are deformed in each element to provide a locking head andtwo leg portions connected by the head, the head and leg portions beingpreferably arranged in a common plane approximately perpendicular to thedirection in which the sequence of elements extends. Connecting portionsof the plastic wire extend in that direction to connect leg portions oftwo adjacent elements.

Provisions should be made for preventing two engaged stringers frommoving in a direction toward each other until the locking heads aredisengaged and slide along the leg portions of the other stringer.Provisions should also be made for securing each element on theassociated carrier member against movement away from the other stringerwhich might result in only partial engagement of the fastener elementsof the two stringers during pull-up. The known slide fasteners of thecontinuous, plastic-wire type are either complex in their structure andcorrespondingly difficult to manufacture, or they do not meet theaforementioned two requirements for securing the proper lockingengagement of their locking heads.

The primary object of the instant invention is the provision of a verysimple slide fastener stringer in which the relative movement of theengaged locking heads is limited to any desired minimal range, and inwhich the elements cannot move relative to the associated carrier tapes.

Another object is the provision of a slide fastener stringer which doesnot require a cord for fixedly securing the interlocking elements in thedesired location and position on the carrier tape.

With these objects and others in view, as will hereinafter becomeapparent, the invention provides a slide fastener stringer of theafore-described type in which the several interlocking elements aresecured to the carrier member by two rows of thread loops extending inthe direction of the element sequence. The loops are locked inrespective positions relative to the carrier member and the leg portionsof the interlocking elements in which the loops engage the leg portionsto secure the same to the carrier member, and the two rows of loops areoffset from the connecting portions of the elements in oppositedirections longitudinally of the leg portions, thereby preventing orlimiting movement of each element on the carrier member longitudinallyof its leg portions.

Other features, additional objects, and many of the attendant advantagesof this invention will readily become apparent from the followingdetailed description of preferred embodiments when considered inconnection with the appended drawing in which:

FIG. 1 shows a sequence of fastener elements for a stringer of theinvention in a perspective view;

FIG. 2 illustrates other fastener elements of the invention in a viewcorresponding to that of FIG. 1;

FIG. 3 shows a sequence of elements closely similar to those seen inFIG. 1 in bottom plan view;

FIG. 4 shows the device of FIG. 3 in top plan view;

FIG. 5 shows the device of FIG. 3 in section on the line V-V; and

FIG. 6 shows one half of a slide fastener chain of the inventionembodying the elements of FIG. 1 or FIG. 4 in fragmentary, perspectivetop view.

Referring now to the drawing in detail, and initially to FIG. 1, thereis seen a length of nylon wire 1 of basically circular cross sectionbent in such a manner that its consecutive longitudinal sectionsconstitute a sequence of identical interlocking fastener elements, onlythree elements of the sequence being illustrated, but the sequencenormally being elongated. The longitudinal spacing of the elements andother dimensional relationships have been exaggerated in FIG. 1 as wellas in FIGS. 2 and 6 of the drawing for the convenience of pictorialrepresentation.

Each fastener element has three leg portions 3a, 3b, 30 which areelongated parts of the wire 1 extending practically in a common planeperpendicular to the length of the element sequence and are parallel toeach other. The bight portion 6 which connects the leg portions 3a and3c into an approximate U-shape is flattened and thereby laterallyenlarged to form a locking head 5. An otherwise undistorted bightportion 7 of the wire 1 connects the leg portions 3b and 3c. The two legportions 3a, 3b are approximately aligned in a longitudinal directionand are each approximately half as long as the leg portion 30 whichconnects the two bight portions 6, 7.

Each connecting portion 2a integrally connects the leg portion 3a of oneinterlocking element to the leg portion 3b of an adjacent element. Twoconnecting portions 2a are thus associated with each element and commonto a pair of adjacent elements. The connecting portions 2a are elongatedapproximately longitudinally of the sequence of elements.

The leg portions 3a, 3b are joined to the associated connecting portion2a by respective bends 8, and extend from the associated bends inopposite directions in the fastener partly illustrated in FIG. 1 whoseelements are of the modified helix type.

The interlocking elements of the stringer partly shown in FIG. 2 are ofthe folded meander type. The connecting portion 22b connects the two legportions 23a of two adjacent elements which are associated with thelocking heads, and the leg portions 23a therefore extend from theconnecting portion 22b in a common direction. The next connectingportion 220 connects two leg portions 23b which extend from theconnecting portion 220 in a direction opposite to that of the legportions 23a.

In the modified interlocking elements shown in FIGS. 3 to 5, the legportions 33a, 33b, 33c and the bight portions 36,37 including the head35 therebetween do not differ significantly from the correspondingportions shown in FIG. 1. The connecting portions 32d each extendbetween a leg portion 33a and a leg portion 33b as described withreference to FIG. 1. They are joined to the leg portions in a bend 38whose concave face is recessed for receiving and holding a sewing threadas will presently be described with reference to FIG. 6. The convexfaces of the two bends 38 in each element abuttingly engage each other.

FIG. 6 shows as much of a slide fastener stringer of the invention as isneeded for an understanding of the invention. The sequence of fastenerelements formed from a round plastic wire 1 in the stringer has beendistorted as discussed above.

The elements are of the type shown in FIG. 1. Their connecting portions2a are in contact with the top face of a carrier tape 12, and theelements are secured to the tape by a seam 10 of double-needle lockstitches. The two needle threads 10a, 10b and the locking underthread10c of the seam 10 are shown loosened for greater clarity. The threadloops formed in a row by the needle thread 10a pass through the tape 12and engage the legs of each element between the connecting portions 2aand the undistorted bight portions 7. The row of thread loops formed bythe needle thread 1012 engage the legs of each element between theconnecting portion 2a and the locking head. The underthread 10c holdsthe loops of the needle threads 10a, 10b in respective positionsrelative to the carrier tape 12 and the leg portions of the severalinterlocking elements in which the loops firmly engage the leg portionsto secure the elements to the tape when the threads are tightened toform knots 15. The two rows of knots formed by the tightened threads areoffset from the connecting portions 2a in opposite directionslongitudinally of the leg portions of the fastener elements.

The two rows of thread loops and knots confine the connecting portions2a therebetween, and limit or prevent relative movement of each fastenerelement and the associated tape 12. As is also evident from FIG. 6, theidentical cooperating other stringer, not shown, of the ultimatelyassembled fastener chain can move toward the illustrated stringer, or tothe right, as viewed in FIG. 6, only until the locking heads on theother stringer are stopped by the nearer row of knots 15. identical,

In actual practice, the sewing threads employed are thick enough almostto fill the space on the leg portions between the connecting portions 2aand the locking heads on the other stringer elements 14, therebylimiting further movement of the latter toward the right to a minimum.Because of the relative dimensions of the elements and of the sewingthreads, the connecting portions 20 must be approximately equidistantfrom the two bight portions 6, 7 to provide adequate anchorage for theneedle thread 10a between the connecting portion 2a and the bightportion 7.

When the underthread 100 is tightened, as is normal in sewing machineoperation, but not seen in FIG. 6, the fastener elements are contractedinto the shape better seen in the modified embodiment illustrated inFIGS. 3 to 5 so that adjacent connecting elements 2a abuttingly engageeach other by their bends 8 (see FIG. 1), and the sewing threads arecradled in the concave bend faces.

The threads 10a, 10b, 100 may be used for securing the meander-typeelements shown in FIG. 2 to the tape 12 without significant changes inthe sewing operation. Substantially the same results are achieved.

It will be appreciated that two rows of thread loops at opposite sidesof the row of connecting portions 2a may be set up by sewing methodsother than those associated with a two-needle lock-stitch machine, andthat the two rows of stitches may be held in the desired positionrelative to each other and to the fastener elements by locking meansother than the illustrated underthread 100. The fabric of the tape 12contributes to the positioning of the needle thread loops in theillustrated embodiment, and may provide sufficient anchorage in othersewing patterns.

The rows of thread loops firmly attach the fastener elements to the tapeand prevent undesired linear or angular movement of the elementsrelative to the tape in any direction. The sections of the wire 1 whichconstitute the several sequential fastener elements are held inprecisely spaced relationship by the thread loops and knots for matchingengagement with the elements of another stringer. The bight portions 7are free from threads. They engage the rails of a slider employed withthe illustrated stringer, and prevent the slider from abrading thesewing threads. A cord is not needed for holding the fastener elementsof the invention in a precisely determined position.

What is claimed is:

1. In a slide fastener stringer having a carrier member; a sequence ofinterlocking fastener elements, said sequence extending in apredetermined direction, said elements being constituted by respectivesequential sections of a continuous plastic wire, each element having aplurality of substantially parallel leg portions elongated in adirection transverse to said predetermined direction, and two connectingportions in common with two other elements respectively, each connectingportion extending in said predetermined direction and connectingrespective leg portions of two adjacent elements; and fastening meansengaging said leg portions and securing said elements to said carriermember, the improvement in the fastening means which comprises:

a. two rows of thread loops extending in said predetermined direction;and

b. locking means holding said loops in respective positions relative tosaid carrier member and said leg portions in which said loops engagesaid leg portions and secure the same to said carrier member, and saidrows of loops are offset from said connecting portions in oppositedirections longitudinally of said leg portions.

2. In a stringer as set forth in claim 1, each element having two bightportions spaced in said traverse direction and defining an approximateU-shape with two of said leg portions, said connecting portion beingapproximately equidistant from said bight portions.

3. In a stringer as set forth in claim 2, the connected leg portions ofsaid two adjacent elements extending from said common connecting portionin opposite directions transverse to said predetermined direction.

4. In a stringer as set forth in claim 2, the connected leg portions ofsaid two adjacent elements constituting a pair of connected leg portionsand extending from said common connecting portion in a common directiontransverse to said predetermined direction, consecutive pairs of saidleg portions extending in opposite transverse directions.

5. in a stringer as set forth in claim 2, said connecting portions beingelongated substantially in said predetermined direction.

6. In a stringer as set forth in claim 1, the two connecting portions ofeach of said elements abuttingly engaging each other.

7. In a stringer as set forth in claim 1, said thread loops abuttinglyengaging said connecting portions.

1. In a slide fastener stringer having a carrier member; a sequence of interlocking fastener elements, said sequence extending in a predetermined direction, said elements being constituted by respective sequential sections of a continuous plastic wire, each element having a plurality of substantially parallel leg portions elongated in a direction transverse to said predetermined direction, and two connecting portions in common with two other elements respectively, each connecting portion extending in said predetermined direction and connecting respective leg portions of two adjacent elements; and fastening means engaging said leg portions and securing said elements to said carrier member, the improvement in the fastening means which comprises: a. two rows of thread loops extending in said predetermined direction; and b. locking means holding said loops in respective positions relative to said carrier member and said leg portions in which said loops engage said leg portions and secure the same to said carrier member, and said rows of loops are offset from said connecting portions in opposite directions longitudinally of said leg portions.
 2. In a stringer as set forth in claim 1, each element having two bight portions spaced in said traverse direction and defining an approximate U-shape with two of said leg portions, said connecting portion being approximately equidistant from said bight portions.
 3. In a stringer as set forth in claim 2, the connected leg portions of said two adjacent elements extending from said common connecting portion in opposite directions transverse to said predetermined direction.
 4. In a stringer as set forth in claim 2, the connected leg portions of said two adjacent elements constituting a pair of connected leg portions and extending from said common connecting portion in a common direction transverse to said predetermined direction, consecutive pairs of said leg portions extending in opposite transverse directions.
 5. In a stringer as set forth in claim 2, said connecting portions being elongated substantially in said predetermined direction.
 6. In a stringer as set forth in claim 1, the two connecting portions of each of said elements abuttingly engaging each other.
 7. In a stringer as set forth in claim 1, said thread loops abuttingly engaging said connecting portions. 